Modern wireless communications devices are expected to work across several different carrier networks, many of which may employ different radio frequency (RF) communications technologies. For example, it may be desirable for a wireless communications device to be capable of interfacing second generation (2G), third generation (3G), and fourth generation (4G) carrier networks. The circuitry used for transmission and reception of RF signals in these different carrier networks may be subject to vastly different operational criteria that have thus far necessitated separate hardware. For example, transmission chains for 3G and 4G carrier networks often utilize average power tracking (APT) circuitry or a combination of APT and envelope tracking (ET) circuitry configured to maximize the efficiency of RF transmission. The circuitry used for transmitting RF signals in 3G and 4G carrier networks is generally not capable of providing adequate power for amplification of RF signals in a 2G carrier network. Accordingly, the hardware support for 3G and 4G carrier networks has thus far been implemented separately from that for 2G carrier networks. The size of the separate hardware has often been a prohibitive factor in providing support for all the desired carrier networks, thereby limiting the ability of a wireless communications device to function in some areas.
Accordingly, there is a need for RF circuitry capable of supporting 2G, 3G, and 4G carrier networks while maximizing the efficiency of the RF circuitry.